Gains millions in cash a drug green and an unlikely man in the middle of at all if physician in a white coat and he's not alone. Federal investigators uncovering a serious problem across this country. Dirty doctors ABC's senior justice correspondent Pierre Thomas has this ABC news exclusive. -- Bring him back this is a drug dealer -- her husband's addiction to powerful painkillers. Drug dealer in a white coat and in the he knows as a doctor that that can -- them. -- needing care she's talking about doctor Norman were there. There were there may look the part of -- kindly doctor zawahiri is on surveillance video committing the crime would you. Federal investigators say the exam is just a sham it only takes four minutes before he prescribed. An undercover informant a painkiller is what we'll. -- Columbus. Doctor were there is part of what federal investigators say is a serious and growing problem. Doctors -- go to the dark side prescribing highly addictive painkillers for -- He gave up his medical license for drug dealing and were there is hardly the only dirty doctor. This doctor was caught on undercover cameras writing prescriptions to phony patients out of a rented motel room drugs on demand. At least 300 doctors were -- -- have been convicted of Medicare fraud in the past three years. Including about 100 who were busted for illegally writing painkiller prescriptions we surprised the doctors were willing to do -- in the numbers that you're saying it's it's mind boggling. -- they start. -- and the cast -- are -- and large homes and vehicles mostly it's greed and greed is apparently what motivated doctor -- -- Investigators seized two point six million dollars in cash and weapons in the case he was convicted of participating in a drug ring involving six Philadelphia area gangs. Who brought him fake patients -- in kickbacks to prescribe painkillers. Then resold the drugs on the street real -- says her husband -- went to dark aware of -- to wean himself off painkillers. Instead she says -- -- stoked his addiction to collect money for doctor visits what he was giving him was just insane amount only 278. Overdosed. Doctor were there was convicted of contributing to his death. Pierre Thomas ABC news Chicago.

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